PayPal, the online payments service that has been growing steadily, is set to become eBay's biggest business very soon.

EBay has spent much of the past two years trying to improve its faltering marketplace business, hoping to increase buyers' trust and clean up the look of its website.

In the meantime, PayPal has thrived as more consumers and merchants use it to send money online.

Its growth is expected to continue in spite of competition from Amazon and Google, which have services that online retailers sometimes offer alongside PayPal.

PayPal bills itself as a shopper's online wallet. Users set up accounts and link them to bank accounts and credit cards, making it easy to transfer cash into the account.

Then users can make payments through PayPal using either their cash balances or the underlying credit card.

PayPal users can also send cash to someone based on as little information as an email address or mobile phone number.

But unlike what happens with a credit or debit card online, PayPal doesn't share your financial information with merchants. That brings peace of mind to people who might otherwise worry about shopping at a site they've never heard of.

PayPal, which began in 1998 as a way for people to beam cash from one Palm Pilot to another, was bought by eBay for 1.5 billion dollars (£0.90 billion) in 2002 and has been a steady performer.

The service charges fees for certain transactions, and in the most recent quarter it reported 688 million dollars (£415.74 million) in revenue, a 15% jump from last year.